Stuck in a rut!

Today I have mostly been sketching out design ideas... although I have plenty of ideas and can picture them working well, I have no files to work with so can't progress. This is really depressing me to be honest. I've started mocking a couple of them up with poor quality images, but feel this is a bit of a waste of time. The only positive I can think of is that it's giving me a taster of the kind of major problems i'll have to overcome when working as a designer for real.